Embodiments of the inventive concepts described herein relate to a method and an apparatus for supplying a liquid to a substrate, and more particularly to a method and an apparatus for applying a liquid onto a substrate.
Various processes such as cleaning, deposition, photographing, etching, and ion implantation are performed to manufacture a semiconductor device. Among the processes, in the photographing process, application, exposure, and development steps are sequentially performed. The application process is a process of applying a photosensitive liquid such as a resist onto a surface of a substrate. The exposure process is a process of exposing a circuit pattern on a substrate in which a photosensitive film is formed. The development process is a process of selectively developing an exposed area of a substrate.
In general, the application process requires a photosensitive film having a uniform thickness on a substrate. Accordingly, a photosensitive liquid is supplied to a central location of a substrate while the substrate is rotated. The photosensitive liquid supplied to the center of the substrate is diffused to the entire area of the substrate by a centrifugal force.
However, the photosensitive film formed on the substrate has different thicknesses in different areas. In particular, the thickness of the photosensitive film becomes thinner as it goes from the center to a periphery of the substrate, which causes an inferiority of the application process.